-96.95% is the change from 491 to 15
Calculation steps:
[( 15 - 491 ) ÷ 491] x 100 = -96.95%
Formula
Percentage change = [(15 - 491) / 491] x 100
Subtract the new number by the original number
15 - 491 = -476
-476 ÷ 491 = -0.9694501018329938
-0.9694501018329938 x 100 = -96.95%